@H. G. Muller: Thank you for the update and the addition of kanji. I may be one of the masochists you mentioned, but I have always played this game with kanji, and so a long-time custom makes this a better choice for me. In all seriousness, though, I am very grateful for your chu shogi and tori shogi offerings. I hope others here get great satisfaction from them, too.

I just updated the package, as there was a bug in WinBoard considering dropping of a Pheasant illegal.
A Japanese website ( http://www10.ocn.ne.jp/~cha/kotenyugi/tori_shougi/tori_syogi.htm ) mentions a different repetition rule: there the side that first created a repeated position must alter its move to prevent it is repeated for the third time, rather than the one playing out of it. Except during a check evasion; you can always evade whichever way you like.
For Shokidoki I adopted the practically identical rule that it is forbidden to repeat, but that perpetual checking is even more forbidden.

My Shogi engine Shokidoki now also can play Tori Shogi (next to regular, Judkins and mini-Shogi). In the WinBoard GUI, it currently looks as follows:

The promoted pieces (not shown here) look like a cannon (+P) and a bird of prey (+Fa).

WinBoard does not have bitmaps for Shogi-style kanji pieces for Tori Shogi, but of course masochistic users that would want these can define their own piece images in WinBoard (through a true-type font).

BTW, the repetition rule mentioned here sounds suspect. (And I could not recognize it in a Google translation of the Japanese Wikipedia, which is even more suspect.) It would imply that a side who starts 'perpetually' checking will win the game, as when the position where his opponent was in check for the first time will finally materialize for the third time, the checked side must now vary, and consequently sacrifice his King, when he is no longer allowed to repeat the only safe evasion. This is very un-Shogi like (and percieved as rather unsatisfactory by orthodox Chess players as well).